1. Industrial Field of the Invention
The present invention relates to a semiconductor device such as an LSI semiconductor device etc., particularly to a laminated wiring structure on the semiconductor device which is composed of an aluminium or aluminium alloy layer and a high melting point conductive layer.
2. Description of the Related Art
A single layer wiring structure using an Al, Al-Si alloy, Al-Si-Cu alloy, etc. has been employed in a wiring for a semiconductor integrated circuit device.
In order to realize the production of a high integration of semiconductor integrated circuit device, however, a laminated structure using an Al or Al alloy layer and a high melting point conductive layer (e.g. TiN, TiW, WNW, WSi.sub.2, MoSi.sub.2 etc.) has recently been employed as a wiring layer. This is because the breakage of wire is liable to occur in the single layer wiring structure using an Al or Al alloy alone, due to stress-migration or electro-migration during heat treatment as the wiring layer employs finer wiring and thinner film. A laminated wiring structure composed of an Al or Al alloy layer and a high melting point conductive layer can prevent the failure of the whole semiconductor integrated circuit device, even if the Al or Al alloy layer is broken, since a high melting point conductive layer maintains its electrical conductivity. However, if the Al or Al alloy wirings are broken at uncertain places, irregular variations between the wiring resistance components affect the operating speed and operational timing of the internal circuits. As a result, the entire characteristics of the semiconductor integrated circuit device are deteriorated.